双燃烧室冲压发动机直连式实验与数值仿真

通过直连式实验和数值仿真,对双燃烧室冲压发动机的流场结构和性能进行了研究.数值仿真采用了半全局多步化学反应机理,计算的压力分布和实验结果基本一致,计算结果表明:中心高温富油燃气与边区空气在混合层内快速反应,热力喉道出现在约0.9m处,出口处的燃烧效率达到了较高水平.提出了结合直连式实验和数值计算的性能估算方法,结果表明:双燃烧室发动机在马赫数为4,高度为17km状态时具有较高的性能,当燃油当量比为0.9时,发动机内推力为8.3kN,内推力比冲为12.29kN·s/kg,更高的燃油当量比将导致超燃进气道不起动. 

Direct-connect experiment and numerical simulation on dual-combustor ramjet

The flow field structure and performance of dual-combustor ramjet (DCR) were investigated through direct-connected experiment and numerical simulations.Semi-global kinetic mechanism was adopted in the simulations.The simulated pressure distributions agreed with the experimental data.Results show that:rapid reaction occurs in the mixing-layer between central high-temperature fuel-rich gas and peripheral air,the thermal choked throat appears at the position of 0.9m,and the combustion efficiency reaches a relatively high level.A method of assessing performance according to experiment and numerical simulation was brought forward.Results show that:the performance of the DCR presented is good under the condition of Mach number is 4.0,altitude is 17km.When the equivalence ratio is 0.9,the internal thrust is 8.3kN and specific impulse is 12.29kN ·s/kg.However,increasing equivalence ratio leads to unstart of inlet.